Family: Paoral membrane prominent, may be large and may project stiffly (Carey, 1992). Genus: Ovoid to ellipsoid; peristome begins at anterior end and extends for 2/3 the body length; a conspicuous membrane at both edges; one to many posterior stiff sensory cilia (Kudo, 1966). Swimming as leaping movement. Species:

31 μm 63 μm 94 μm; x 640